1. Field of the Invention
The present invention relates to a spacer case for an outboard motor and an outboard motor, and more particularly, it relates to a spacer case for an outboard motor arranged between an upper case and a lower case and an outboard motor including the spacer case.
2. Description of the Related Art
An outboard motor including a spacer case is known in general. Such an outboard motor including a spacer case is disclosed in Japanese Patent Laid-Open No. 2003-214162, for example.
Japanese Patent Laid-Open No. 2003-214162 discloses an outboard motor including an upper case, a lower case, and a spacer case. The spacer case is arranged between the upper case and the lower case. This spacer case has a function of adjusting the vertical position of the lower case (propeller) with respect to the upper case (the mounting position of the outboard motor on a boat body). In a state where the upper case is positioned above the lower case through the spacer case, studs are inserted from the side of the lower case to the side of the upper case. These studs are longer than the spacer case in a vertical direction. The studs are fastened to the upper case, such that the spacer case is fixed to the upper case as well as to the lower case (is fastened to the upper case together with the lower case).
In the outboard motor described in Japanese Patent Laid-Open No. 2003-214162, however, the length (the length of the spacer case) between the upper case and the lower case varies according to the mounting position of the upper case on the boat body, and hence the studs according to the length of the spacer case must be provided. In other words, in the case where a plurality of spacer cases having different lengths are prepared, a plurality of sets of studs designed according to the lengths of the spacer cases must be prepared, and hence it is difficult to increase the number of various spacer cases. Thus, it is preferable to flexibly accommodate a difference in the length of the spacer case.
In the outboard motor described in Japanese Patent Laid-Open No. 2003-214162, the studs longer than the spacer case must be fastened to the upper case, and hence distortion is easily generated in the studs. Consequently, the fastening power (axial force) of the studs may be reduced due to the distortion of the studs when the spacer case is fixed, particularly in the case where the spacer case is long. Thus, also in the case where spacer cases having various lengths are provided, it is preferable to make it possible to reduce or prevent the reduction in the fastening power (axial force) of the studs and securely fix the spacer case to the upper case and the lower case.